Ultra wide-band radar antenna for concrete penetration

• US 5,640,168 A
• Filed: 08/11/1995
• Issued: 06/17/1997
• Est. Priority Date: 08/11/1995
• Status: Expired due to Fees

• Current Assignee: Zircon Corporation
• Original Assignee: Zircon Corporation
• Inventors: Long, James C., Marshall, Noel H. C., Heger, Charles E.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): PHAN, THO GIA
• Application Number:
  US08/522,818
• Time in Patent Office: 676 Days
• Field of Search: 343/785, 343/786, 343/776
• US Class Current: 343/786
• CPC Class Codes: H01Q 13/02 Waveguide horns

Abstract

A pyramidal horn antenna that decreases ringing in radar systems that are placed against a solid volume of e.g. concrete or wood for finding an object in or behind the solid volume. The antenna includes a solid, pyramid-shaped dielectric, the pyramid shape including a rectangular base and four triangular sides that extend from the base to meet at the apex of the pyramid. Two conductive triangular plates overlay opposite ones of the four sides of the pyramid, each of the plates including an electrical connection for coupling the plate to a radar system. The pyramid-shaped dielectric has a dielectric constant that approximates the dielectric constant of the solid volume, and therefore provides an impedance match between the antenna and the solid volume.

Claims

1. A pyramidal horn antenna for transmitting or receiving electromagnetic signals into or from a surface, the antenna comprising:

a pyramid formed of a solid dielectric material, the pyramid including a rectangular base and four triangular sides, the four sides defining four planes that extend from the base to meet at an apex of the pyramid; and

first and second triangular plates, each of the plates formed of a conductive material, the first plate overlaying and in contact with one of two opposite ones of the four sides, the second triangular plate overlaying and in contact with the other of the two opposite ones of the four sides;

wherein length of to first and second triangular plates substantially covers the respective opposite ones of the four sides; and

wherein the pyramid and the first and second triangular plates reduce ringing associated with transmitting electromagnetic signals into the surface.

2. The antenna of claim 1, wherein the pyramid is formed of a dielectric material having a dielectric constant .di-elect cons._R of approximately 10.

3. The antenna of claim 1, wherein the angle between the first and second plates is approximately 53°

.

4. The antenna of claim 3, wherein the rectangular base includes two opposite edges approximately 1.75 inches in length and two opposite edges approximately 1.5 inches in length, and wherein the first and second triangular plates extend toward the apex from the two opposite edges approximately 1.75 inches in length.

5. The antenna of claim 1, wherein the conductive material includes copper.

6. The antenna of claim 1, wherein the conductive material includes silver.

7. An antenna system for transmitting and receiving electromagnetic signals into or from surface, the system comprising:

an enclosure having a plurality of chambers; and

a plurality of pyramidal horn antennas, wherein each of the antennas is contained in a corresponding one of the chambers, each of the antennas including;

a pyramid formed of a solid dielectric material, the pyramid including a rectangular base and four triangular sides, the four sides defining four planes that extend from the base to meet at an apex of the pyramid; and

first and second triangular plates, each of the plates formed of a conductive material, the first overlaying and in contact with one of two opposite ones of the four sides, the second triangular plate overlying and in contact with the other of the two opposite ones of the four sides;

wherein each of the first and second triangular plates substantially covers the respective opposite ones of the four sides; and

wherein the pyramid and the first and second triangular plates reduce ringing associated with transmitting electromagnetic signal into the surface.

8. An antenna system for transmitting and receiving electromagnetic signals through a solid volume to locate objects within the volume, the system comprising:

an enclosure defining a plurality of chambers, the enclosure having a face configured to abut the solid volume; and

a plurality of pyramidal horn antennas, wherein each of the antennas is contained in a corresponding one of the chambers, each of the antennas including;

a pyramid formed of a solid dielectric material, the pyramid including a rectangular base and four triangular sides, the four sides defining four planes that extend from the base to meet at an apex of the pyramid; and

first and second triangular plates, each of the plates formed of a conductive material;

wherein the face of the enclosure includes a lossy gasket having holes through which the base of each of the antennas is exposed to the solid volume.

9. The antenna system of claim 8, wherein each pyramid is formed of a dielectric material having a dielectric constant .di-elect cons._R of approximately 10.

10. The antenna system of claim 8, wherein the first and second triangular plates of each antenna have an angle between them of approximately 53°

.

11. The antenna of claim 10, wherein each rectangular base includes two opposite edges approximately 1.75 inches in length and two opposite edges approximately 1.5 inches in length, and wherein the first and second triangular plates extend toward the apex from the two opposite edges approximately 1.75 inches in length.

12. The antenna of claim 8, wherein the conductive material includes copper.

13. The antenna of claim 8, wherein the conductive material includes silver.